Slip draft device in a spinning machine



Aug. 25, 1964 KuNlo AoKl SLIP DRAFT DEVICE IN A SPINNING MACHINE FiledApril 5. 1960 R 0 T M E 0 V W 0 F5 M United States Patent 3,145 432 SLIPDRAFT DEVICE 1N ,A SPINNING MAcllNE Kunio Aoki, Osaka, Japan, assignerto Daiwa Boseki Kabushiki-Kaisha, Osaka, Japan, a company of Japan FiledApr. 5, 1960, Ser. No. 20,161 4 Claims. (Cl. 19-259) This inventionrelates to a slip draft device in a spinning machine, wherein a sliproller is provided between front and back rollers.

In a known slip draft device, the spindle of a slip roller is slidablymounted in a guide slot, and the roller is in contact with thecylindrical surface of a bottom roller mounted on a fixed bearing, andan intermediate bottom roller is provided under the slip roller and isspaced slightly therefrom. A sliver or fleece, which is called a strandhereinafter in this specification, fed from a pair of back rollerspasses through the contacting parts between the slip roller and thebottom rollers, and is drawn by a pair of front rollers, being draftedbetween the back and slip rollers and again between the slip and frontrollers as usual.

The main object of this invention is to obtain a means to automaticallyadjust the space between the intermediate roller and the top slip rolleraccording to the thickness of strands treated, whereby the strand ofiibers is always held at substantially a constant pressure regardless ofvariation of its thickness.

ln the accompanying drawing,

FIGURE l is a schematic front elevation of a slip draft device accordingto this invention;

FIGURE 2 is a sectional view taken on lines 2-2 of FIGURE l; and

FIGURE 3 shows a moditication of a part of FIG- URE 2.

On a roller stand 3 of a spinning frame are adjustably fixed slideblocks 4, 5 and 6, and back, middle and front bottom rollers 7, 8 and 9are rotatably mounted on respective blocks, and are driven by drivingshafts, not shown. The spindles of top rollers 1G, 11 and 12 areslidably held in respective guide slots 13, 14 and 15 by means ofsleeves 10a, 11a and 12a, and each roller is loaded by its own weightand well known loading means such as springs or weights, and is rotatedby the contacting friction with respective bottom rollers. The chainline A denotes the trace of a sliver or fleece to be drafted.

The large top roller 11 between the front and back rollers, which iscalled slip roller, is slidably tted in the guide slot 14 and rests onthe bottom roller 8. The spindle 17 of a roller 16, which is called anintermediate roller in this specification is mounted on a floating block18 sitting on an elastic bed made of coil springs 19. Needle bearings 20are employed in the oating block for the holding roller.

The cylindrical surface of the intermediate roller presses only lightlyagainst the cylindrical surface of the slip roller under the influenceof the springs 19 acting on floating block 18 when no strand of fiber ispresent between the intermediate roller and the top roller, and thecontacting pressure can be adjusted by means of adjusting screws 22.However, since the load on the slip roller is far larger than theelastic force of the springs 19, the nipping action of the slip roller11 on middle bottom roller 8 is not affected by the adjustment of thescrews. Moreover, the pressure of intermediate roller 16 on slip roller11 is never great enough to do more than straighten and align the fibersas they slip over roller 16.

A modification of the floating bed is illustrated in FIG- URE 3, whereina bellows 21 is employed instead of a spring, and the pressure of afluid in the bellows can be 3,145,432 Patented Aug. 25, 1964 "Iceadjusted by a regulating valve provided in the pipe led from a fluidsource. Y

The adjusting screws 22 are set to adjust the pressure of the springs 19on the bearing blocks 18. These adjusting screws force the springsagainst the bearing blocks so that when the intermediate roller 16 isVspaced from the slip roller 11 bya strand of fibers of average thicknesspassing between these rollers, the desired pressure will be Aexerted onthe strand of fibers by the intermediate roller. In a spinningoperation, if a thicker part of a strand passes between the slip rollerand the intermediate roller, the bearing blocks k'1S are pushed by thestrand against the spring or bellows so that the spacing isautomatically varied.

In known slip draft devices, the bearing blocks for the intermediateroller are fixed keeping a definite clearance between the slip rollerand the holding roller. fore, if a thicker part of a strand passes theclearance, the pressure acting on the strand is abnormally increased,while if a thinner part passes the clearance, almost no pressure acts onthe strand, so that the strand can not be smoothly drafted and eventhreads cannot be obtained. And, if the spacing is required to bechanged, the bearing blocks of the slip roller have to be removed in thehorizontal direction when the machine is not in operation. For thispurpose, the slide block on which the slip roller is mounted isgenerally divided into two pieces, upper and lower, and the upper piecehaving therein the slot for the slip roller can be adjusted relative tothe lower one which has the intermediate roller mounted thereon.

According to the present invention, however, the bearing blocks for theintermediate roller are resiliently maintained in the guide slot, sothat the roller automatically varies its position so that the pressureagainst the strand is kept almost constant, so that the diiiicultieswhich were heretofore caused by the predetermined spacing of the rollersare overcome, and the drafting. action is smoothly carried out under aproper condition resulting in a superior spinning effect. In View ofthis the adjustment of the bearing blocks need not be changed if theaverage size of the sliver is not greatly changed.

I claim:

l. In a drafting mechanism, the combination. of a pair of top and bottomfront rollers, a slip roller immediately behind the top front roller, abottom roller against which said slip roller runs and having a diametersmaller than the diameter of said slip roller for gripping a sliver asit is drawn toward the front rollers, an intermediate roller betweensaid bottom front roller and said bottom roller and contacting said sliproller and being driven by said slip roller, and resilient mountingmeans on which said intermediate roller is mounted resiliently urgingsaid intermediate roller against said slip roller, whereby the clearancebetween the slip roller and the intermediate roller is varied by theresilient mounting means during the operation of the mechanism dependingon the thickness of the sliver which is passing between the slip rollerand the intermediate roller, and the fibers are always nipped at asubstantially constant pressure.

2. In a drafting mechanism, the combination of a pair of top and bottomfront rollers, a slip roller immediately behind the top front roller, abottom roller against which said slip roller runs and having a diametersmaller than the diameter of said slip roller for gripping a sliver asit is drawn toward the front rollers, mounting means on which said sliproller is mounted and on which said bottom roller is iixedly mounted, anintermediate roller between said bottom front roller and said bottomroller and having a diameter less than the diameter of said bottomroller and contacting said Slip roller and being driven by said sliproller, a pair of bearing blocks slidably mounted Therein said mountingmeans for movement substantially perpendicular to the direction of thesliver and on which said intermediate roller is mounted, and resilientmeans acting on said bearing blocks and resiliently urging saidintermediate roller against said slip roller, whereby the clearancebetween the slip roller and the intermediate roller is varied by theresilient means during the operation of the mechanism depending on thethickness of the sliver which is passing between the slip roller and theintermediate roller, and the fibers are always nipped at a substantiallyconstant pressure.

3. The combination as claimed in claim 2 in which said resilient meanscomprise a spring acting on each bearing block, and means bearing onsaid spring for adjusting the compression of said spring.

4. The combination as claimed in claim 2 in which said resilient meanscomprise a bellows acting on each bearing block, and means connected toeach bellows for adjusting the fluid pressure therein.

References Cited in the tile of this patent UNITED STATES PATENTS1,579,414` Thoma Apr. 6, 1926 1,696,553 Owen Dec. 25, 1928 2,323,882Shaw July 6, 1943 2,624,919 Spencer v Jan. 13, 1953 FOREIGN PATENTS n,

740,859 Great Britain c; Nov. 23,1955

1. IN A DRAFTING MECHANISM, THE COMBINATION OF A PAIR OF TOP AND BOTTOMFRONT ROLLERS, A SLIP ROLLER IMMEDIATELY BEHIND THE TOP FRONT ROLLER, ABOTTOM ROLLER AGAINST WHICH SAID SLIP ROLLER RUNS AND HAVING A DIAMETERSMALLER THAN THE DIAMETER OF SAID SLIP ROLLER FOR GRIPPING A SLIVER ASIT IS DRAWN TOWARD THE FRONT ROLLERS, AN INTERMEDIATE ROLLER BETWEENSAID BOTTOM FRONT ROLLER AND SAID BOTTOM ROLLER AND CONTACTING SAID SLIPROLLER AND BEING DRIVEN BY SAID SLIP ROLLER, AND RESILIENT MOUNTED MEANSON WHICH SAID INTERMEDIATE ROLLER IS MOUNTED RESILIENTLY URGING SAIDINTERMEDIATE ROLLER AGAINST SAID SLIP ROLLER, WHEREBY THE CLEARANCEBETWEEN THE SLIP ROLLER AND THE INTERMEDIATE ROLLER IS VARIED BY THERESILIENT MOUNTING MEANS DURING THE OPERATION OF THE MECHANISM DEPENDINGON THE THICKNESS OF THE SILVER WHICH IS PASSING BETWEEN THE SLIP ROLLERAND THE INTERMEDIATE ROLLER, AND THE FIBERS ARE ALWAYS NIPPED AT ASUBSTANTIALLY CONSTANT PRESSURE.